Initiation of self-expanding high-temperature synthesis (SHS) in the Al–Ti–C system in the process of spark plasma sintering (SPS) of specimens allows obtaining a material with high density, which contains MAX-phases. A simple rheological theory has been developed, which can describe SHS and SPS processes under certain conditions. Within the framework of this model, the processes of pressing and extrusion at uniaxial pressure are considered. The dependence of the relative density of the powder mixture on time is scaled by the factor of the ratio of pressure to the viscosity of the invariant base of the material. Analytical time dependences of the plunger speed and sample height, as well as the time required to achieve the specified value of the relative density of the Al–Ti–C material, which allows us to predict and analyze the compression of powder mixtures in the SPS process were obtained.

The object of research is the mechanisms of synthesis of nanocarbon structures in the process of electric high-voltage breakdown of hydrocarbons. The problem to be solved is the purposeful synthesis of various types of nanocarbon with small losses of raw materials. Mechanisms of nanocarbon formation in the process of high-voltage electric breakdown of hydrocarbons have been established. It is shown that a high-voltage breakdown leads to a cascade of chemical transformations. As a result of transformations, lower gaseous hydrocarbons are formed due to the destruction of molecules and higher ones – as a result of polymerization, and as a result of dehydrocyclization and polymerization with the participation of metal catalysts – various carbon nanostructures. The possibility of targeted synthesis of fullerene-like structures, nanotubes with diameters from 10 to 50 nm, nanofibers, and films is demonstrated. Experimental studies have confirmed that the qualitative and quantitative composition of nanocarbon can be varied in a wide range. With an increase in the number of carbon atoms or the number of C–C bonds in the raw material molecules, other things being equal, the practical yield of solid nanocarbon increases. It was determined that the synthesis of structured nanocarbon from a mixture of hydrocarbon gases, formed as a result of high-voltage breakdown of liquid hydrocarbons, actively occurs on the nickel-chromium catalytic surface. An increase in the area of the catalytic deposition surface leads to an increase in the yield of nanocarbon. The study of the ability of the obtained nanocarbon samples to absorb electromagnetic radiation confirmed the potential of the method of high-voltage breakdown of hydrocarbons for the synthesis of materials that weaken electromagnetic radiation at a frequency of 25 to 38 GHz. The greatest weakening is observed for samples consisting mainly of carbon nanotubes and nickel nanoparticles

— Based on experimental and theoretical data, thermodynamic analysis of possible chemical reactions occurring in the titanium–aluminum–hexamethylenetetramine system under conditions of self-propagating, high temperature synthesis (SPHTS) was performed. It was shown that, under the above conditions, the MAX-phase Ti 3 AlC 2 can be predominantly formed at cooling down the material up to temperatures lower than 1100 K. The highest negative values at T = 298 K are those of enthalpy and Gibbs energy of the combustion reaction of hexamethylenetetramine combustion in the air, which allows for the assumption that this is the starting reaction for the synthesis process under study.

— The processes associated with self-propagating high-temperature synthesis (SHS) in the Ti−Al−C powder system are studied, with hexamethylenetetramine amine (С 6 H 12 N 4 ), polytetrafluoroethylene, and amorphous carbon (aC) used as carbon precursors. The key parameters of SHS and way the it unfolds are shown to be determined by the carbon precursor used and a technique employed for preparing initial powder samples. With the indicated carbon precursors, we are able to prepare nanostructured composite materials containing titanium carbide and the Ti 2 AlC MAX phase, while the Ti 3 AlC 2 MAX phase is formed under specific conditions in the Ti−Al−С 6 H 12 N 4 and Ti−Al−aC powder systems.

The results of experiments to reduce the instability of spark load parameters using a model of spatial electrospark dispersion for metal and graphite granules by varying the capacitance of a capacitor bank and charging voltage are presented. The conditions for spark process stabilization in a layer of metal and graphite granules are determined. The influence of the capacitance of a capacitor bank and charging voltage on the efficiency of energy distribution in the discharge circuit is shown.

Distinctions and general regularities of the electric characteristics of discharges have been experimentally studied using a model of spatial electrospark dispersion for different parameters of an electric circuit, with the replacement of water by a hydrocarbon medium, the presence or absence of synthesized powder materials in it, and the application of graphite granules in the place of metal ones. The results are presented in this work.

Possible mechanisms of the formation of carbon nanomaterials (CNMs) with the electrodischarge treatment (EDT) of liquid hydrocarbons are proposed. It is shown that the EDT of hydrocarbons results in a cascade of chemical transformations such as destruction (breaking of C-C bonds), dehydrogenization (breaking of C-H bonds), and polymerization (formation of new C-C bonds). The qualitative and quantitative composition of all EDT products (gaseous, insoluble solid CNM, and substances dissolved in the initial liquid) may be widely varied and significantly depend on the organic liquid used.

The basic processes occurring in a conductor exploding in a current skinning mode are the propagation of a nonlinear magnetic diffusion wave in the conductor and the formation of low-temperature plasma at its surface. An experimental study of the phenomenon of nonlinear magnetic diffusion into conductors in magnetic fields of induction rising at a rate up to 3·109 T/s was carried out on the MIG generator capable of producing a peak current up to 2.5 MA within a rise time of 100 ns. It has been found experimentally that the average velocity of a nonlinear magnetic diffusion wave in an aluminum conductor placed in a strong magnetic field (up to 300 T) rising at a high rate (on average, 3·109 T/s) is (2.7÷3.3)·105 cm/s. This is comparable to the velocity of sound in aluminum under normal conditions and reasonably agrees with predictions of numerical simulations.

The effect of the processes of the electrodischarge treatment of organic fluids and appearing gases onto carbon nanomaterials (CNM) and hydrogen has been experimentally studied. It is shown that the three-stage treatment of organic fluids and appearing gases in a flowing mode allows for the increase the efficiency of raw material processing and for obtaining various CNM with different electrophysical properties depending on the type of the raw material and catalysts used.

The effect of the processes of the electrodischarge treatment of organic liquids and the generated gases on carbon nanomaterials (CNM) and hydrogen has been experimentally studied. It is shown that the three-stage treatment of organic liquids and the generated gases in a flow mode allows the increase of the efficiency of the raw material processing and obtaining various CNM with different electrophysical properties depending on the type of the raw material and catalysts used.

The paper deals with an experimental investigation of the dependence of output powder-like products in the process of continuous electrodischarge synthesis of carbon nanomaterials and pyrolytic treatment of concomitant gas mixtures on the structure and properties of raw materials – liquid organic compounds – alcohols, acyclic and cyclic saturated hydrocarbons.

A possibility of fabrication of metal-carbon nanocomposites by electrical-discharge method is studied. Morphological characteristics, structure and electrical conductivity of powder samples of fabricated metal-carbon nanomaterials are determined.

It was studied experimentally how the yield of the powder products in the process of continuous electrodischarge synthesis of carbon nanomaterials and the pyrolytic treatment of the concomitant gas mixtures depends on the structure and properties of the raw materials. Liquid organic substances-alcohols and acyclic and cyclic saturated hydrocarbons-were used as the raw materials.

The possibility to produce metal-carbon nanocomposite materials by the electrodischarge method is studied. The morphological characteristics, composition, and electrical conductivity of powder samples of the produced metal-carbon nanomaterials are determined.

A continuous and nonwaste process is proposed, which consists of a set of simultaneous operations on electrical discharge treatment of the carbon liquid in the reactors. The liquid is exposed to high temperatures and pressures generated by the discharge plasma, selection and separation of the processed substance in the filter or centrifugal separation device. Then follows recirculation of the purified material in the closed hydraulic system. The manufactured product, depending on the method used for selection and separation, is a thick, pasty mass, or a dry powder mixture containing various modifications of carbon fullerenes, nanotubes and nanodiamonds in the amount of up to 10% of the total weight. The prototype of the electrical equipment has been buit to provide the processing performance from 0.02 to 1.5 kg/hour. It has the maximum installed power of 5 kWA, and its specific energy consumption ranges from 0.1 to 10 MJ/ kg. The pulsed power source with microprocessor control has been designed for industrial applications. It allows achieving the maximum pulse repetition rate value of 200 Hz, which is limited by the time of the medium relaxation and dielectric strength restoration in the discharge gap. This ensures flexible regulation and a shift in the corresponding processing performance of the single-reactor systems in the range from 0.4 to 30 kg/hour. This technology is complemented with the developed method for enrichment of the produced ultrafine powder. It consists in the original sequence of physical and chemical methods (magnetic separation, acid treatment, chromatographic purification, etc.) and can increase the target selectivity of the processed products.